After radical prostatectomy (RP) for clinically localized prostate cancer (CaP) 15-40% of men will show clinical or biochemical evidence of disease progression. Many of these failures are due to occult metastatic disease. This project explores the phenomenology of prostate cancer dissemination through application of reverse transcriptase polymerase chain reaction (RT-PCR). The specific aims of this project are: 1) To test the hypothesis that extra-prostatic tumor cells are present in most patients with clinically localized CaP yet clear following RP in those patients cured of CaP, but do not clear or later reappear when recurrent disease develops. 2) To examine the phenomenology of RT-PCR results in the bone marrow following prostate seed implantation (PSI) and compare the results with those following RP. 3) To test RT-PCR assays for the CaP markers, hK2 and PSMA in bone marrow specimens and examine the effect of various treatments (RP, radiation, Hormones) on the expression of these markers alone and in combination with PSA. 4) To assess new RT-PCR assays for markers of virulence developed by the technical core. 5) To test new semi-quantitative gene expression assays the hypothesis that as disease severity increases the number of cells expressing genes associated with prostate cancer will increase. Pre-operative and serial post-operative bone marrow aspirates will be collected from patients undergoing radical prostatectomy. Specimens will be analyzed with an RT-PCR assay for PSA expression. Results will be compared with long-term (5 year) disease free survival and biochemical recurrence as defined by a chemiluminescent assays with a biological detection limit of 0.008 ng/ml. A similar study will also be performed on patients undergoing PSI. The banked cDNA from the RP and PSI patients will also be tested by RT-PCR assays described in the Technical Core, which may help assess the metastatic potential of cell detection in the bone marrow, will also be studied. Finally, we will examine with transcription mediated amplification whether semi-quantitative techniques, which will allow us to know the relative expression of PSA, PSMA, and hK2, provide additional information beyond that provided by the current qualitative assays.